1. Field of the Invention
The present invention relates generally to medical instruments for aiding in the implantation of an endoprosthetic implant. More specifically, the present invention relates to a cutting guide for preparing a distal femur to accept the femoral component of a uni-condylar total knee implant during a minimally invasive surgical procedure.
2. Description of the Related Art
Partial knee replacement surgery has become relatively common. According to traditional practice, such surgeries require a relatively large incision through the soft tissue above a patient's knee, through which the various aspects of the partial knee arthroplasty are performed. These aspects include removing diseased bone and cartilage from the patient's knee and preparing the distal femur and proximal tibial to receive synthetic implants. For example, when a patient's knee deteriorates, cartilage wears away and the patient becomes either bow-legged or knock-kneed, depending on which side of the knee, medial or lateral, is diseased. Accordingly, surgery must be performed to realign the knee by seating artificial implants to replace the diseased portion of the patient's knee. Part of such a surgery involves resecting bone from the diseased side of the distal femur, such that the bone is appropriately shaped to receive an articulating artificial femoral component. In order to make sure such cuts are properly performed, and that soft tissue is not unnecessarily damaged, instruments called cut guides, which are well known in the art, are removably attached to the appropriate section of the distal femur, and are used to provide a mechanical stop to the saws introduced into the surgical field to make appropriate cuts on the distal femur. Larger surgical incisions naturally involve greater damage to skin, muscle connective tissue and the like, collectively referred to herein as soft tissues. As damage to a patient's soft tissue is increased, so too, is the time required for the patient to recover from surgery. This fact can cause a variety of negative economic effects. For example, a longer recovery time for a partial knee arthroplasty patient means a longer hospital stay. Physicians and hospitals, therefore, can accommodate fewer surgeries, and thus, the price to patients and their insurers increases for each individual surgery. Moreover, longer recovery times result in patients missing more time from work which may result in economic detriments for both the patient and his or her employer. However, a smaller incision results in a smaller scar and a generally more pleasing aesthetic effect for the patient.
Accordingly, minimally invasive surgical (“MIS”) techniques have become available, which greatly reduce the size of the incision. Such smaller incisions, in the range of about 6-10 millimeters, vastly reduce the amount of time necessary for the patient to fully recover from a partial knee surgery. Thus, a need exists for minimally invasive surgical instruments that fit into smaller incisions, yet still useful to surgeons.